1. Field
This relates to a handler, and in particular, to a method for transferring a test tray within the handler.
2. Description
A handler may be used to perform electrical tests on packaged chips at the conclusion of a packaging process. Such a handler transfers packaged chips from a user tray to a test tray and supplies the test tray containing the packaged chips to a tester including a test board having a plurality of sockets. The packaged chips in the test tray are brought into contact with the sockets to perform an electrical test on the packaged chips. The packaged chips are graded according to the test results, and the handler transfers the graded chips from the test tray to appropriate user trays based on the grading. As the packaged chips on the trays move within the handler for loading, testing and unloading, movement of the various devices that convey the trays should be coordinated for efficient, error free processing.